<h2>Problem 206</h2>
<div style="color:#666;font-size:80%;">06 September 2008</div><br />
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<p>Find the unique positive integer whose square has the form 1_2_3_4_5_6_7_8_9_0,<br /> where each &ldquo;_&rdquo; is a single digit.</p>
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